Piston



NOV- 2, 1948. k BA D 2,452,714

PISTON Filed April 7, 1945 MROL D 8.4 RNARD IN V EN TOR.

' Patented Nov, 2, 1948 UNI ED PATENT omen PISTON v Harold Barnard, Houston, Tex" ass'lgnor to The Whitehead Bros. Rubber Company, a corporation of New Jersey Application April 7. 1945, s ar No. 587,059

This invention relates s Olaims.- (o1; ace-2s) to pump pistons and particularly to a piston of the type that is capa-' ble of providing the service required in-slush pumps which are used in the circulation of drilling fluids in the rotary method of well drilling.

As is well known, slush pumps that are used in the'rotary method of drilling wells, utilize pistons which are secured to piston rods for reciprocation in pump cylinders which are provided with valves at opposite ends so that the piston has a working stroke in each direction. Enormous pressures are exerted upon these pistons which are in constant contact with abrasive fluids, and it is therefore necessary that the piston be of rugged construc tion, and that it be so designed. that'the efiect of destructive forces acting hereon are minimized.

It is also desirable that ready repair and/or replacement of the piston, or parts thereof, be

possible.

It is the primary object of the invention to provide a piston which "is simple, is of sturdy construction, and which is so designed that replacements and repair may be readily effected.

Another object is to provide a piston having a plurality of packing rings of identical construction. I

, Another object is to provide a piston having expansible packing rings and cooperating means for admittingfiuid pressure to the rings from the,

respective ends of the piston.

A still further object is to provide a piston having telescopic body members which cooperate with an interposedfiange to form packing receiving grooves about the piston.

It is also an object of the invention to provide a a piston packing ring of improved construction.

The foregoing objects, together with other objects and advantages of the invention, will be more fully apparentfrom. the following description considered in connection with the accompanying drawings in which:

Fig. 1 is a sectional view through a piston em bodying the invention, the view being taken on line |l in Fig. 2;

Fig. 2 is a plan view of the piston shown in upperand lower quadrants shown in section are respectively taken on lines 2-2 and 3-3 in Fig. 1.

The piston l embodyin the invention includes a body 2 comprising telescopic members 3 and 4, of which the former is reduced at 5 to receive the latter, and also to receive the interposed flange 6. The end of the reduced portion 5 of the membet 3 is threaded at I to receive the nut 8 whereby .the component parts of thepiston are releasably held in assembled relation.

Fig. 1, the view being partly in section. The

Members 3fand 4 have flanges I 5 and H5 at their outer ends to cooperate with the flange 6 and with the surfaces 20 and 2| on these members to provide spaced annular grooves about the piston assembly to receive the packing rings 22 t and 23. ,It is to be noted that the sidewalls of the respective flanges are tapered so that the side walls of the grooves extend convergingly outwardly, and alsov that-these walls merge into the peripheral cylindrical surfaces of the flanges in the. arcuate surface 25. These features of con- --struction aitl'in directive flow of material-of, the

packing rings to maintain a seal and to compensate for wear, as will more fully appear hereinafter. I

The body member 3 H at the upper end" of the piston forms a continuation. Thebore 9' is of a size and configuration to receive the end of a piston rod to which I the piston is attached for normaluse within a pump cylinder.

The packing rings 22 and 23 have toroidal chambers?! therein and, as will be fully explained, means is provided to admit pressure fluids to these chambers. Since the material of the rings 22 and 23 is resilient but noncompressible, and since the rings are restrained for movement in the direction of the walls of the packing spaces,

' the application of pressure within the chambers 21 is instrumental in producing such radial dis-. placement or flow of the ring material that the peripheral surfaces thereof are maintained in intimate engagement with the walls of the surrounding cylinder. To desirably control the lines of flow of the packing material and to thus en-' hance thelife of the packing rings, one or more layers of fabric 29, shown by dotted lines in Fig. 1. are embedded within the material of the rings 22 and 23, such fabric extending radially from the inner to the outer surfaces of the rings and passing the chamber 21 at opposite sides thereof.

The packing rings are provided with side openings 30 in their outer faces and these openings ,are in mating relation with the openings 3| and 32 in the respective end flanges.

To assure this mating relation of the openings in the flanges and the rings, one or more axially extending,

grooves 33 are provided in each of the surfaces 20 and 2| to receive complementary key-like projections on the inner surface of the packing rings 22 and 23.

v has a central bore 8 ha ing tapered wall ID of which; the cylindrical-wall wall within which It seems apparent that this construction assures that pressure exerted upon the ends of the piston ris' transmitted throu h t e openings; in and I 32to the chamber 21 within the respective packing rings. It. also seems apparent, that the grooves 33 are so oriented that the rings -Hand- 1 23 are intercl'iangeable.-

The structure advantag es, the mode of operation of the piston as above described are I believed apparent. By way of amplification andreiteration, it willvbe pointed out that'the piston is assembled by first placing the packing ring'23 upon the ,surface 2l in a manner that the pas-. I. sages 30 and Si are in alignment,'the inward pro v jection on the packing ring fitting within the groove 33. Flange 5 is'ithen placed in engagement with the, side -wal-l of' th ring, 23 and the shoulder I2 on. themember 3. The ring 22 is then placed upon the telescoping body member A with the openings 3'0 and 32 of the ring and" I j, .4 sure fluid fromrthe end of the'piston ber within the adjacent packing ring.

4. A piston comprising telescopic body mem bers having 'end flangesand axially extending.

cylindrical surfaces thereon, aflange interposed between said members and forming, with said cylindrical surfaceaa pair of packing receiving spaces. a chamberedpacking ring within each of,

said spaces, and means for restraining each of 5*. A' piston including an assembly comprising a body having end flanges and an intermediate flange'forrningpacking receiving grooves about the assemblyhthe opposed flange faces in each member in alignment. This assemblyfis their positioned upon the reduced portion! of the member 3 and the completeassembly is secured in a unitary structure by means of the nut ,8.

C parts, or repair thereof, is believed apparent, it

ingflared peripheral edges overlying said curved being pointed out that the component parts of 1 the piston are so designed and constructed that repair may be readily effected, or that, where desired, replacement of parts is facilitated.

Broadly the invention comprehends a slush pump piston which is simple, and effective, and

which is inexpensive to construct and maintain. I

What is claimed is: I V 1. A piston including telescopic body sections having flanged outer ends, a flange interposedand clamped between said body sections whereby annular spaces are provided to receive packing rings about the periphery ofthe pistonassembly, the opposed faces in said spaces tapering convergingly outward, and a packing ring in each of said spaces.

2. A piston including telescopic body having-flanged outer ends, a flange interposed and clamped between said body sections whereby annular spaces are provided to receive packing rings about the periphery of the piston assembly,

the opposed faces in said spaces tapering convergingly outward, a packing ring in each of saidend flanges and an intermediate flange forming annular peripheral spaces, a packing ring in each of said spaces, an annular pressure chamber in g each of said rings, and means for admitting pressections Y 6. A piston including of said grooves being tapered eonvergingly outwardly and merging with the periphery of the flanges m a curved-surface, and a, packing ring filling each of said'grooves, said packing ring havsurface to provide annular seal lips about the Piston; Y I I I I an assembly comprising a body having end flanges and an intermediate flange forming packing receiving grooves about the assembly, the opposed flange faces in each of said grooves being tapered convergingly outwardly and merging with the periphery of the flanges in-a curved surface, a packing ring filling each of said grooves, said packing ring having flaredperipheral edges overlying said curved surface to provide annular seal lips about the piston, and means responsive to fluid pressure upon said piston for expanding the packing ,rings radially of. the assembly.

HAROLD BARNA IS.

, REFERENCES crrnn f v c The following references are of record in the filed this patent:

UNITED STATES PATENTS to the cham- 

